Method and apparatus for automatic strength regulation and filtration of brines



May 16, 1950 Filed Jan. 12, 1949 D. W. KAUFMANN METHOD AND APPARATUS FORAUTOMATIC STRENGTH REGULATION AND FILTRATION 0F BRINES 3 Sheets-Sheet lDa/e W. Kaufman/7 ATTO RN EY5 KAUFMANN 2,508,170 1c STRENGTH May 16,1950 w.

METHOD AND APPARATUS FOR AUTOMAT REGULATION AND FILTRATION OF BRINES I5Sheets-Sheet 2 Filed Jan. 12, 1949 INVENTOR Da/e W. j faufmam BY Que n.M M V- ATTORNEYS May 16, 1950 AUFMAN N 2,508,170 METHOD AND APPARATUSFOR AUTOMATIC STRENGTH REGULATION AND FILTRATION OF BRINES Filed ,Jan.12, 1949 3 Sheets-Sheet 3 INVENTOR Da/e 'W Kaufman/7 ATTORNEYS PatentedMay 16, 1950 METHOD AND ABPARATU'S FOR AUTOMATIC STRENGTH REGULATION ANDFILTRA- TION OF BRINES Dale W. Kaufmann, Buffalo, N. Y., assignor toInternational SaltGQmpany, Inc., Scranton, Pa.

Application January 12, 1949, Serial No. 70,504

(Cl. 13.-'Z78) 11 Claims.

This invention relates-to a method and automatic apparatus formaintaining .a process regressive brine :atany certain desired strength,in spite of salt subtraction or water addition incidental to. theprocess; such as would otherwise undesirably diluteior weaken the brine.The invention also relates to a method and automatic apparatus forcontinuously filtering from a circulating brine any solidsor undesirableforeign materials which may'zenter the'brine in the course of its use.Howeverrtheinventionis not neces sarily restricted to :filtration ofprocess brines in conjunction with strength regulation of processbrines, inasmuch 'as. eitherof the :above stated objects may beaccomplished:alone, if and when desired.

Various industries employ circulating brines which should preferably bemaintained substantially :at prescribed strengths, such as for examplein connection with spray decks and unitcoolers. in meat packing plants,gravity separators in canneries, and the like. These process brines,tend continuously 'to become weakened due to absorption of water fromthe air or from the product being treated, or by subtraction of saltfrom the solution; and in order to maintain a prescribed brine strength,either dry salt or a stronger :fortiiying brine "must "be added to theprocess vbrine. To avoid undesirable fluctuations in the process brinestrength, the-dry-salt or the fortifyin-g brine must be addedcoincidently with and at a rate exactly equal to that of the brinedilution. In addition to becoming weakened, circulating process *brines:o'ften pick up foreign materials such. as rust scale, particles ofth-esubstances being processed, sawdust, strings, lint, and other fllterablesubstances.

A principal object of this invention isithe D vision ofani-mproved'method and apparatus for automatically maintaining acirculating process brine at any prescribed strength, regardless 'of theextentito which and the rate at which the brine absorbs water or losessalt.

Another object 'of'therinventionisthe provision of an improved apparatuswhereby any foreign solids inthe process'brineror'in the-hrinefortifyingsalt :arefiltered "out, whereby a brine-which is substantiallycolorless-or decreasedin color-content and free 'from solids isdelivored"forfortify ing the process brine; andwhereby-continuouslay-passing of'a portion-101 all oftheprocess brine tlnough theapparatusofrthe inventionoperates to remove foreign'solidsifromthetotalvolume of process brine.

Another robjectbf the invention is the provision of an improvedapparatus for dissolving drysalt to make substantially saturatedfortifying brine, using unsaturated process brine as "the salt.

This invention is particularly applicable for" use for example inconjunction with the known Lixate process for making saturated brinefrom, rock salt, the salt dissolving apparatus for; which is illustratedand described in simple form in United States Patent No. 1,928,008to'Thomas; Forster Courthope. However, this invention is notnecessarilyzrestricted to use with the Court hope apparatus.

To these and ,otherends, this invention consists, in the constructionand arrangement of parts that will appear from the followingdescriptionwhen readin conjunction with the accompanying drawings, the novelfeatures beingqpointed out the claims at the end of the specification.

The present invention contemplates an automatic brine strength controlapparatus which in one form may provide for a column of fortifying brineof definite height which is of relatively high strength and specificgravity to be arranged in hydraulically balanced'relation with a columnof process brine which is of a greater height and relatively lowerstrength and specific gravity. When the two aforesaid columns of brineare properly connected and are in hydraulic balance there is no flow of'fortifying brine into the process'brine. However, if and as the processbrine weakens, an unbalance results, and brine from the columnof'fortifying brine, if the'latter is maintained. at its prescribedheight by supply from an outside source of 'fortifying brine, willautomatically start to flow into the weakened process brine until theincreasing specificgravity of the latter restores the hydraulic balance.The flow of ,fortifying brine into theprocess brine then ceasesautomatically, It is to be understood that whereas, the apparatus of theinvenuonmay conven n y emp oy a ,fu ly a urat d salt solution as the.iortiiyi g brine, h in tion is not solimited and thefortifying brinemaybe of any specificgravity greater than that got the processbrine. Also,the invention contem-v plates that the apparatus may employa supply ofiortifying brine which is maintained under definite pressure atthevinterface between the fortifying brine and the process brine, by anysuitable means in lieu of-the means shown and described-in detailherein, such-as for example a mechanically pressured system controlledby a pressure regulating valve.

More specifically, the invention contemplates a novel apparatusproviding a hydraulic connection between the two brines in such a waythat the fortifying brine will not appreciably tend to flow into andmingle with the process brine at the juncture therebetween, except underconditions of hydraulic unbalance.

In the drawings:

Fig. l is a diagrammatic view of a brine strength control apparatus.constructed according to one possible embodiment of this invention;

Figs. 2, 3, 4 are fragmentary illustrations of modified forms ofhydraulic column connection devices such as are adapted for use in lieuof the connection device illustrated in conjunction with the apparatusof Fig. 1;

Fig. 5 is a view corresponding to Fig. 1, but of an apparatus includinga dry salt dissolving device for providing the fortifying brine; and

Figs. 6-7 are views of similar apparatus including means for regulatingthe strength of the process brine at will.

The apparatus of Fig. 1 comprises a storage tank I I which functions asa storage tank for the process brine I2. A pump I3 is shown asconnecting the tank outlet to a pipe M for distribution of the brine tothe brine-using process, from which it returns through a pipe I5 to thetank II in a weakened or diluted condition, such as may be due to waterabsorption during the proc ess use. The absorbed water increases thebrine volume, and therefore an arrangement is provided for discharge ofthe excess as through an overflow pipe I6, thus maintaining a constantliquid level in the tank II as indicated at IT.

A fortifying brine supply I 8 is provided in a tank I9, and the processbrine is automatically fortified and held at its prescribed strength byflow of relatively stronger brine I 8 from the tank I9 through a pipe 20into the tank II. A valve 2| is provided in the pipe 20 and is left openduring operation of the apparatus. The fortifying brine I8 need notnecessarily be a saturated salt solution but should preferably be ofconstant strength, and must always be stronger and of higher specificgravity than the brine l2. The brine I8 is held at a constant level 22in the tank I9 by means of a float valve 23 and replenished as neededfrom an outside source through a pipe 24; and it will be noted that thebrine level 22 is lower than the brine level !'I, and as illustrated inFig. 1 the ratio of brine depth B to brine depth A for any desiredstrength of process brine I2 when using a specified fortifying brine ISwill be found by dividing the prescribed specific gravity of the processbrine l2 by th known specific gravity of the fortifying brine I8.

The difference in vertical elevation. between the fortifying brine level22 and the process brine level I! is determined by the relative specificgravities and hydraulic heads of the two brines I2-I8. Thus, referringspecificall to Fig. 1, the hydraulic column length A of process brine I2may be arranged for any convenient tank depth, whereupon the brinecolumn length 13 will be readily determined according to the desiredstrength of the process brine I2. For example. it maybe wished to holdthe process brine i2 constant at 1.139 specific gravity while using afortifying brine I8 which is saturated at 1.204 specific gravity. Insuch case the brine level I2 must be located in such relation to brinelevel I1 that A .l39=B 1.204.

If A for example is 10.00 feet, then B will be 9.46 feet. The elevationdifference 0 will be then 10.00 feet minus 9.46 feet or .54 feet and thebrine level 22 must therefore be located .54 feet below the brine levelI7. The hydraulic heads in tanks II and It will then balance, and therewill be no substantial flow through the pipe 20 and. the two brines willnot substantially mix provided the connection be tween the two brines isarranged to prevent such mixing, as will be explained hereinafter.However, whenever the brine I2 becomes lower than 1.139 in specificgravity, the stronger brine I8 will flow from tank I9 into tank II andinto the weaker brine I2 until the latter again attains 1.139 specificgravity, whereupon transfer flow of brine I8 will cease.

A means of preventing appreciable spillage of the fortifying brinethrough the pipe 20, except in response to an unbalanced hydraulic head,is essential to the operation of the apparatus; because the strongerbrine would otherwise bleed continuously into the weaker brine anddisplacethe latter due to their different specific gravities. Forexample, as shown in Fig. 1, this ma be accomplished by turning the pipe20 upward at its discharge end portion 25, thereby creating between thetwo brines a horizontally disposed interf ace of small area whereby whenthe two brines are in hydraulic balance they tend to mingle only by adiffusion process which proceeds at such slow rate as not to matter inordinary practice.

Inasmuch as the process brine I 2 may be flowing into and out Of tankII, in the course of its use, at rates such as may cause considerableagitation and fluid turbulence in the region of the discharge pipe end25, it may be advisable to protect the brine interface at the pipe end25 by a suitable hood or cap 26 as shown in Fig. 2. Such a hood willprotect the brine interface from agitation such as might undulyaccelerate the normally slow and unimportant rate of diffusion of thestrong brine into the weaker brine. Another means for protecting thebrine interface against agitation is shown in Fig. 3, wherein thedischarge end of the pipe 20 is formed with an inverted trap 27; thepipe discharge end 25 being thereby pointed downwardly. The smallportion of strong brine in the right-hand leg and upper horizontalportion of the trap 21 will diffuse downwardly in response to the forcesof gravity into the brine I2; but the strong brine in the left-hand legof the trap will remain substantially at level 23 and will not flowappreciably into the brine I2 except under unbalanced hydraulic headconditions.

.' Still another arrangement for protecting the brine interface againstagitation is shown in Fig. 4 wherein a trap 29 is inserted in the pipe20 outside of the tank I I and arranged in such a way that the smallportion of stron brine I8 in the horizontal pipe between the trap I9 andthe tank I I can diffuse out into the brine I2, but no furtherappreciable flow of strong brine I8 from th trap 28 into the pipebetween the trap and the tank II will take place except under unbalancedhydraulic head conditions.

The apparatus of Fig. I requires a source of fortifying brine I8 to beobtained from an outside source and supplied to the tank I9 through thepipe 24. The fortifying brine may be made by dissolving salt in water,but the dissolution water required to provide the brine I8, if madethus, eventually displaces an approximately equivalent volume of brineI2 in the tank II. This displaced volume of brine I2 overflows throughthe pipe I6 and causes a large loss and waste of 'salt in addition to;the inevitable: overflow loss; resulting. from process brine-volumeincrease due: tor water absorption in. the;.course ofzprooesseusages ofrthebrine; Therefore; tooliminate; such extra. loss of salt throughdissolution inc-water;v the; supplysaltshouldabe dissolved,in'-,the;.unsaturated-z process brine l2: which: may betaken; either,;=from pipe i4; pipe, or any other, conveniently: disposed 1301171011105:the brine,- circulating, system; For example, an apparatus; embodyingthe: known ,Lixate; process. for making; saturated ,brinefrom-rookosalt, is particularly adapteditoipermit; use;oi;theprocessbrine I2;fo r salt:dissolution-,.

a-Ildyis ifurthermoreadvantageous-because:itxalso:

continuously filters foreign solid, materials from; the solventbrine;Fig; 5 shows anzapparatusfor; strength regulation of brineszusingthenprincipley. ofihydraulic; balance; as heretofore describe inconjunction: with. means: providing forthe: dissolution of: the.fortiiying, salt by, the. process 1 brine 32, as the, solvent; and,furthen embodying; filtration of; the; process: brine, Thegapparatusaaincludes, a. tank ,31ireceiving. the; processzbrina 32': and having. a;brine.- deliveryconduit; 33- and; pump -.3; t :andbrine return conduit'35; The-over:- flow; is: indicate.d at 3,6; the top brine;-level-1 at3.11, and the; brine: interface: level at 33;. salt: dise solvingapparatusfifl; embodying the. Iiixate process, asdllustrated. and;described-.-in UnitedoStates Patent No.. 1,928,008 'isishown:ll'l5.ii,S"l'6GBlV-.\ ing a supply of dryv salt. 4 l To dissolve:the-salt? a; portion; of r the process brine 32.? is=.taken fronn the;pipe 33 and' led tothe: dissolveri 4!}; through: apipe 42; flowythroughwhich is controlled-auto. matically by a fioat operatedva1ve-as.-explainedin the patent. The dissolver: produces fully;saturated and clear brine which isfiltered free from all solids such asocoasionallytenter. the process brine or occurin the salt M; Thedissolver this fully automatic in its: operation: and inasmuch as thesolvent brine held at at constant level 43 by operation of thedissolverfloat controlled valve, the salt- M feeds in to the dissolverat the same rate dissolution-takes place. Also, solvent brine from thepipe enters the-=- dissolver when, and only at the-"same rate assaturated brine is withdrawn from the dissolver through a pipe 44. Thissaturated fortifying brine flows from thedissolver it-throughthe;pipe-d4 and into the process brine- 32-:oftank- 31i when and as it isrequired; for automatic hy draulic balance with the brine 32; A trap 65?is inserted in the pipe 44 to protect-tho interface betweenthe brinesas; explained hereinaloove;

In Fig. 5, the dissolver 4B is placed at'suoh an elevation that thebrine levels i and 3! occupy approximately the same verticalrelationship as do the corresponding levels 22iand il" in Fig, 1; Insuch case the vertical portion of pipe 4.4 between levels 43 and 33 actsas a standpipcfq substantially saturated brine, thus taking the, placeof tank It in Fig. 1, butproviding the same hydraulic head B. ofsubstantially. saturated brine. to balance against the hydraulic head. Aof, process brine. Therefore, if, and asrthe, process brinein tank 3!weakens; anunbalanceresults and filtered saturated brine fiows-into-theprocess; brine tank through the pipe- 4 until the: in-: creasingspecific gravity of'the brine; 323 restores: h hydr lic; nce; ereupon:ans er f; brine ceases; Due to; the automaticEoperat? not; the dissolverdo the dissolution brine-.entersithe; dissolv rt shr pez Mat the sameate-that saturated ine; is :witlidrawnr hr iish hernino;

as and when brine iswithdrawn from the letter,

6: 44:, thereby o din the iquidlevel. flzconstantz attall jtimesrWhereas; the: apparatus arran mentsr f" ss- 1; and 5;embodyrelativelyfixed liquid levels for:

', specific strengths; of brines, if the strength of;

; feasible to accomplish this .byraising or, lowering.-

oneyof thetanlss or -thedissolver, inwhichcase the-change in therelative elevations; of thetwo liquid levels may be accomplishedbyothermeans; r. examp e as: shown; n. F the ap a atus oigFig. 5--may bemodifiedzto include a standpi-pe' 7B on case the dissolveridllislocatedwitm its 1 aid level 43; at a convenient: substantial:-

above the desired liquid; level 5a in; the,- standpipe 50. Saturatedbrineefrom the dissolver; 4i! flows through a pipe 5 5 to thetanlg-Eilzonly and-is-held constant therein at level 5Z'by an?adjustable float controlled valve" 56: Thetank. ooa-isiconnectedio thetank, 31- byapipe Stain; which is placed; a. trap 55% to protect theinterface between the saturated brine-and. the process,

the float device, of, the adjustable valve 56- isadjusted to cause the.desired. change in the. level 52 Another arrangement whereby, theprocess brine 31 may. be easily. adjusted,- to,v different. strengths"is .shown in-Fig. 7. Thisarrangement. alsoiavoidsithe. necessity of-'arigid pipe-con nection betweenthe fortifying. brine standpipe 5t. andtheprocess brine tank 33. In this case a siphon pipe fioisarrangedwithits suction pipe.

leg 5!. immersed in brine in the tank 55, and its, discharge pipe legfizimmersed in the brine 32 in tank; 3,1. Thebr-inein the tank isreplenished and heldat a, constant. level 6.4, regardless. of brinewithdrawals therefrom, by the Lixate Ill 98% ess usin the. dissolver Ml,with itsliquid level tarplacediat. the same elevation as level 5st. in.the tankfifl As in the case ofFig. 6., the salt inthe dissolver 4.1! isdissolved by a. portion of the process brine 32, taken from the brinecirculating pipe Mby a, pipe 5,6. Saturatedbrine from. the dis= olverditfiowsto the tank lilithrougha pipe t8. I f andas theliquiddevelEAtends to drop due to brine withdrawal,- an equivalent. quantity ofbrinenautomaticallyr enters-through pipe 68 from thedissolver All,toholdthebrine level 54 at a constant, elevation; However the method ofhQlding the, level 64, constant is. not. necessarily restrictedltouse of--the dissolver dfi because this mas ie-accomplished for. exam l a h wnin liig. l, as applied to control ofthelevel 22in tank I9.The;dischargeapipeleg 52x01 the siphon 56 must he-arrangedto protect theinterf ace between the; fortity-ingbrine, and the process. brinev by Ihaying' -the disehargeend pipe turned upwardly as shown at iii, for thereascnspexplained in connection with the discharge-end 25, of the pipe2% in Eigrli, Qr, if preferred, the interfacs may, be protected-byan-arrangement'as shown in either Fig. 2 or Fig; 8, or by. someequivalent means.

In the apparatus ot Fig-.- '7 the ratio of the, hy-

foheadBrfim hyd aulic head A ha eed ns or owerin 1 11 73. p on: na a: tus ho din he: protest brine; 2 at ny desired strength, depending uponthe ratio selected. The

siphon pipe 60 may be raised, lowered, and held at any desired elevationby various simple devices; for example as by suspending it from hooks 12disposed at various heights. The siphon pipe 60 may be filled withfortifying brine by priming it by means of aspirator or ejector 13inserted in the pipe 62. The aspirator I3 is operated by a portion ofthe process brine taken from the pipe 34 by means of a pipe 14 and aflexible hose 15. The aspirator 13 might, alternatively, be operated bywater under pressure passing through the flexible hose [5.

Although only a few embodiments of the invention are shown and describedherein, it will beunderstood that this application is intended to coversuch changes or modifications as come within the spirit of the inventionor the scope of the following claims.

I claim:

'1. An apparatus for automatically maintaining hydraulic balance betweena column of predetermined relatively high and constant strength brineand a column of relatively low strength brine and for causing automaticfeeding of said predetermined high strength brine into said column oflow strength brine for maintaining the brine in the, latter column atuniform strength, said apparatus comprising container means for saidcolumns of brine and liquid passage means interconnecting said containermeans adjacent the lower ends thereof, said passage means including anupwardly directed portion arranged in open communication with the lowstrength brine container-portion to accommodate said different strengthbrines in opposed relation therein whereby to provide a horizontallydisposedinterface between said different strength brines, and means formaintaining the levels of the brines in the columns constant relative toeach other and the level of said high strength brine below the level ofsaid low strength brine.

2. An apparatus for automatically maintaining hydraulic balance betweena column of predetermined high and constant strength brine and a columnof low strength brine and for causing automatic feeding of brine fromthe high strength brine column to the low strength brine column formaintaining the brine strength in the low strength brine column atsubstantially unifdrm strength, said apparatus comprising means fluidlyinterconnecting said columns adjacent the lower ends thereof and havingan upwardly directed portion in open communication with the low strengthbrine column at the position of the junction between said differentstrength brines when they are in hydraulic balance whereby to provide ahorizontally disposed interface between said different strength brinesat the position of junction therebetween, and means for maintaining thelevels of the brines in said columns constant relative to each other,the level of the brine in the high strength column being intermediatethe level of the brine in the low strength column and the level of saidinterface.

3. An apparatus for automatically maintaining a supply of regressiveprocess brine at substantially uniform strength, comprising a containerreceiving said process brine at a constant head therein, a secondcontainer receiving a supply of fortifying brine therein at a constanthead and strength, and a liquid passage system maintaining said twosupplies of brine in hydraulic balance and for causing automatic feedingof 8 brine from said fortifying brine container into said process brinecontainer to maintain said process brine at uniform strength, saidpassage system comprising means fluidly interconnecting said containersadjacent the lower ends thereof,

and including an upwardly directed portion in open communication withthe low strength brine container and. providing a horizontally disposedinterface at the junction between said process and fortifying brines.

4. An apparatus for automatically feeding a relatively highpredetermined constant strength brine into a relatively low strengthbrine for maintaining the latter at substantially uniform strength, saidapparatus comprising separate container means for said brines, and meansfluidly interconnecting said container means, said means including ahydraulic trap having an upwardly directed portion arranged toaccommodate said different strength brines in opposed relation thereinwhereby to provide a horizontally disposed interface between saiddifferent strength brines with the high strength brine below the lowstrength brine therein, and means for maintaining the levels of thebrines in said containers constant relative to each other and the levelof said high strength brine below the level of said low strength brine.

5. An apparatus for automatically maintaining a supply of regressiveprocess brine at substan-' tially uniform strength, comprising acontainer receiving said process brine at a constant head therein, asecond container carrying a supply of salt, means conducting a portionof the process brine into said second container to produce a supply ofconstant strength fortifying brine, a third container arranged toreceive a supply of said fortifying brine therein at a constant head,and means fluidly interconnecting said first and third containers formaintaining said two supplies of brine in hydraulic balance and forcausing automatic feeding of brine from said fortifying brine containerinto said process brine container to maintain said process brine atuniform strength, said fluid interconnecting means comprising meansinterconnecting said containers adjacent the lower ends thereof andincluding an upwardly directed portion providing a horizontally disposedinterface at the junction between said process and fortifying brines,with the high strength brine below the low strength brine, and means formaintaining the levels of the brines in the containers constant relativeto each other and the level of said high strength brine below the levelof said low strength brine.

6. An apparatus for automatically maintaining a supply of regressiveprocess brine at substantially uniform strength and in clean filteredcondition, comprising a container receiving a circulating portion ofsaid process brine at a constant level therein, a second containercarrying a supply of granular salt, means circulating a portion of theprocess brine into said second container as required whereby to producea supply of constant strength fortifying brine and at the same time tofilter said process brine through said salt to absorb filterablematerial from said process brine and to produce a clean fortifyingbrine, a third container arranged to receive a supply of said fortifyingbrine therein at a constant level, and means fluidly interconnectingsaid first and third containers for causing automatic feeding of brinefrom said fortifying brine container into said process brine containerto maintain said process brine at uniform strength,

said fluid interconnecting means comprising means interconnecting saidcontainers adjacent the lower ends thereof and including an upwardlydirected portion providing a horizontally disposed interface at thejunction between said process and fortifying brines, with the highstrength brine below the low strength brine therein, and meansmaintaining the levels of the brine in said containers constant relativeto each other and the level of said high strength brine below the levelof said low strength brine.

'7. An apparatus for automatically maintaining a supply of regressiveprocess brine uniformly at adjustable strength, comprising a firstcontainer receiving said process brine, means maintaining the processbrine in said container at a constant head, a second container receivinga supply of constant strength fortifying brine therein at a predescribedconstant head, a liquid passage system maintaining said two supplies ofbrine in hydraulic balance and for causing automatic feeding of brinefrom said fortifying brine container into said process brine containerto maintain said process brine at uniform strength, said passage systemcomprising means fluidly interconnecting said containers and includingan upwardly directed portion in open communication with the low strengthbrine container providing a horizontally disposed interface at thejunction between said process and fortifying brines, and

means for regulating the prescribed constant head of said fortifyingbrine Within said second container to thereby cause regulation of thestrength of said process brine.

8. An apparatus for automatically maintaining a supply of regressiveprocess brine at desired strength, comprising a container receiving saidprocess brine at a constant head therein, a second container carrying asupply of salt, means conducting a solvent into said second container vto produce a supply of constant strength fortifying brine, a thirdcontainer arranged to receive a supply of said fortifying brine thereinat a specified constant head, means fluidly interconnecting said firstand third containers for maintaining said two supplies of brine inhydraulic balance and for causing automatic feeding of brine from saidfortifying brine container into said process brine container to maintainsaid process brine at uniform strength, said fluid interconnecting meanscomprising means interconnecting said containers and including anupwardly directed portion providing a horizontally disposed interface atthe junction between said process and fortifying brines with the highstrength brine below the low strength brine therein, and control meansfor adjustably regulating the head of said fortifying brine in saidthird container to cause regulation of the strength of said processbrine.

9. An apparatus for automatically maintaining a supply of regressiveprocess brine at desired strength and in clean filtered condition,comprising a container receiving a circulating portion of said processbrine at a constant level therein, a second container carrying a supplyof granulated salt, means circulating a portion of the process brineinto said second container as required whereby to produce a supply ofconstant strength fortitying brine and at the same time to filter saidprocess brine through said granular salt to absorb filterable materialfrom said process brine and to produce a clean fortifying brine, a thirdcontainer arranged to receive a supply of said fortifying brine thereinat a constant level, and means for maintaining the levels of the brinesin said containers constant relative to each other and the level of saidhigh strength brine below the level of said low strength brine, and asiphon conduit interconnecting the brines within said first and thirdcontainers for maintaining said two supplies of brine in hydraulicbalance and for causing automatic feed ing of brine from said fortifyingbrine container into said process brine container to maintain saidprocess brine uniformly at desired strength, said conduit systemcomprising conduit means bodily adjustable to different elevations forcontrolling the strength to which the process brine is maintained, andsaid conduit including an upwardly directed portion disposed in said lowstrength brine container providing a horizontally disposed interferenceat the junction between said process and fortifying brines.

10. An apparatus for automatically maintaining a supply of regressiveprocess brine at desired strength, comprising a first containerreceiving a portion of said process brine at a constant level therein, asecond container arranged to receive a supply of high predeterminedconstant strength fortifying brine therein at a constant level below thelevel of brine in said first container, and a. siphon conduitinterconnecting the brines within said containers for maintaining saidtwo supplies of brine in hydraulic balance and for causing automaticfeeding of brine from said fortifying brine container into said processbrine container to maintain said process brine at desired strength, saidconduit including an upwardly directed portion disposed in said lowstrength brine container providing a horizontally disposed interface atthe junction between said process and fortifying brines.

11. An apparatus for automatically maintaining a supply of regressiveprocess brine at desired adjusted strength, comprising a first containerreceiving a portion of said process brine at a constant level therein, asecond container arranged to receive a supply of high predeterminedconstant strength fortifying brine therein at a constant level below thelevel of brine in said first container, a siphon conduit interconnectingthe brines within said containers for maintaining said two supplies ofbrine in hydraulic balance and for causing automatic feeding of brinefrom said fortifying brine container into said process brine containerto maintain said process brine at desired strength, said conduitincluding an upwardly directed portion disposed in said low strengthbrine container providing a horizontally disposed interface at thejunction between said process and fortifying brines, and said siphonconduit being bodily adjustable to different elevations for regulationof the strength at which said process brine is maintained, and means forpriming said siphon conduit with fortifying brine.

DALE W. KAUFMANN.

No references cited,

